Appeal 3363495

The appeal is allowed and planning permission is granted for conversion of integral garage to habitable accommodation and erection of double storey extension to the side and rear and installation of a side dormer at [site address] , Hillingdon, [postcode] , in accordance with the terms of the application Ref 16721/APP/2024/3357, and the plans submitted with it, subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: location plan, 100, 190, 200 and 290.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those of the existing building.

I consider that the main issue in this case is its effect on the character and appearance of the area.

[site address] is a detached two storey house of brick and tile hanging located at the head of a short cul-de-sac. It has a distinctive architectural style with a steeply pitched main roof and catslide roof to the side over an integral garage. The other properties in the cul-de-sac share similar brick and tile hanging materials and steep roofs, with some being similar in design to No. 12 and others having a strong two storey bay feature with gabled roof to the front elevation and catslide over the garage.

The relevant policies in this case include BE1 of the Hillingdon Local Plan: [name] – [name] (November 2012) and DMHB11, DMHB12 and DMHD1 of the Hillingdon Local Plan: [name] – Development Management policies (January 2020) (the local plan). These relate to the design quality of new development, including extensions, which, among other things, should be sympathetic to the host building, harmonise with the local environment and not have an adverse impact on the character and appearance of the street scene.

The Council raises no objection to the conversion of the garage into habitable accommodation and associated alterations to the front elevation or to the depth of the projection of the extension to the rear in the context of the existing layout and footprint, and I see no reason to disagree with this view.

The proposed first floor element would be a relatively substantial addition at the side, projecting from the side roof behind the catslide over the garage. However, it would be set back over 5m from the front elevation and well down from the highest point of the main roof. I consider that its overall scale, siting, roof pitch and proposed materials would result in a development which would be subordinate to the main house and sympathetic to the architectural style and design features of the house itself and others in the street.

The proposed side dormer would result in additional bulk at roof level, but I consider that its design, roof pitch and materials would also be sympathetic to the character and appearance of the house.

I have taken account of a similar example in [address] which is different in that that house is one of those with a two storey gabled bay element which makes the first floor extension less apparent and unobtrusive in the overall composition. Two houses in [address], although some distance away, are of a similar design with similar extensions. I consider that the set back from the front, matching roof pitch and materials have resulted in properties which harmonise with the character and appearance of the street scene.

No. 12 is in a prominent location at the head of the cul-de-sac and the proposed extension would be readily visible from the street. However, I consider that its design and materials would complement the existing character and appearance of the area.

I conclude that the proposal would not harm the character and appearance of the building or the street scene and surrounding area and that in this respect it is consistent with local plan policies BE1, DMHB11, DMHB12 and DMHD1.

For the reasons given above, the appeal is allowed.

I have considered the conditions put forward by the Council, having regard to the tests set out in the Framework. A condition detailing the plans is necessary to ensure the development is carried out in accordance with the approved plans and for the avoidance of doubt. A condition relating to the materials is necessary in order to ensure the satisfactory appearance of the development.